"I should have"

or "Why didn’t I"

or "How could I have been so stupid?"

or "I did it again!"

Instead of beating yourself up, what if you said,

"Next time I will…."

"For future reference, I now know…"

"I did that until now, now I…"

We are all going to be making bunches of mistakes in this life (at least if we are really living.) But, it is what you learn from them that is important. Use mistakes to decide how you want to live from now on.